There are many ways to make those swiftlet feel comfortable in entering a new BH.
One of the way is to make the entrance hole larger or looks larger than before.
The reason why you do this is to allow those wild birds to come to the entrance hole and feel easy to enter and fly out if they feel unsafe.
They can enter in in single file or in a large group with no fear of feeling trapped inside.
To those who uses deep tunnel to distribute these visitors to all the floors the best is to have a window that is high to allow those birds to fly at a sharper angle towards the respective floors.
What I did in Parit Buntar Perak was something that you can to learn.
First I open the main entrance hole wider by hacking the side (1 foot) and lower part (1.5 feet).
I then install a wooden frame made from excess nesting planks. The wood frame will be easier to install those tweeters.
To make this entrance door looks larger my worker pain the entrance hole perimeter with black paint.
The paint lining was about 8 inches wide.
This painting works makes the entrance hole looks larger by 16 inches to it side and 16 inches more to the height.
From far those birds will have the impression that the window is pretty wide and safe to fly in and rush out, in case of feeling threaten.
This widening method will be a useful tool for your BH.
The are a few problems associated with enlarging the hole especially owl entering and too much light.
These two issues can be easily resolve if you know how to.
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